userdel Command

Purpose

Removes a user account.

Syntax

userdel [ -r] login

Description

The userdel command removes the user account identified by the login parameter. The command removes a user's attributes without removing the user's home directory by default. The user name must already exist. If the -r flag is specified, the userdel command also removes the user's home directory.

If the AIX_USERDEL_RECURSIVE_DEL environment variable is set, the userdel command recursively deletes the directories and files that belong to the removed user. If another user uses the same home directory, the files and directories of the user is preserved. If the directory of the deleted user contains content owned by a different user, the directory ownership of the user is changed to the user nobody with a permission of 777 and a sticky bit set. This operation is performed for the continued access of the directory and its content for the affected users by using the same home space. It is very important to change the permission and ownership of the affected directories to a new user immediately after running the userdel command. The system administrator can change the permission and ownership setting of the affected directories to a new user to prevent illegal access.

Only the root user or users with UserAdmin authorization can remove administrative users. Administrative users are those users with admin=true set in the /etc/security/user file.

Flags

Item Description
-r Removes the home directory of the user. Files located in other file systems must be searched manually and deleted. Removing the home directory, which is shared by other users, might leave the system in an inconsistent state.

Exit Status

Item Description
0 The command completed successfully.
>0 An error occurred.

Security

Attention RBAC users and Trusted AIX users: This command can perform privileged operations. Only privileged users can run privileged operations. For more information about authorizations and privileges, see Privileged Command Database in Security. For a list of privileges and the authorizations associated with this command, see the lssecattr command or the getcmdattr subcommand.

Examples

  1. To remove the user davis account and its attributes from the local system, enter:
    userdel davis

Location

/usr/sbin/userdel

Files

The userdel command has read and write permissions to the following files.

Item Description
/etc/passwd Contains the basic attributes of users.
/etc/security/user Contains the extended attributes of users.
/etc/security/user.roles Contains the administrative role attributes of users.
/etc/security/limits Defines resource quotas and limits for each user.
/etc/security/environ Contains the environment attributes of users.
/etc/security/audit/config Contains audit configuration information.
/etc/security/lastlog Contains the last login attributes of users.
/etc/group Contains the basic attributes of groups.
/etc/security/group Contains the extended attributes of groups.